Direct X-ray and electron-beam lithography of halogenated zeolitic imidazolate frameworks

Metal–organic frameworks (MOFs) offer disruptive potential in micro- and optoelectronics because of the unique properties of these microporous materials. Nanoscale patterning is a fundamental step in the implementation of MOFs in miniaturized solid-state devices. Conventional MOF patterning methods suffer from low resolution and poorly defined pattern edges. Here, we demonstrate the resist-free, direct X-ray and electron-beam lithography of MOFs. This process avoids etching damage and contamination and leaves the porosity and crystallinity of the patterned MOFs intact. The resulting high-quality patterns have excellent sub-50-nm resolution, and approach the mesopore regime. The compatibility of X-ray and electron-beam lithography with existing micro- and nanofabrication processes will facilitate the integration of MOFs in miniaturized devices.

Picture: High-resolution EBL patterning of 100 nm thick ZIF-71 films. a,b, SEM (left) and AFM (right) topographic images of the ZIF-71 film with 50 nm trenches (a) and 200 nm lines (b). c,d SEM images of the ZIF-71 film with 100 nm (c) and 60 nm (d) lines. e,f, SEM images of the ZIF-71 film with 40 nm holes (e) and a grid with a 30 nm line width (f). Scale bars: a,b, 1 μm; c, 1 μm (200 nm for inset); d, 200 nm (100 nm for inset); e,f, 100 nm (50 nm for inset).

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